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Servo tank gauge for high accuracy liquid level measurement

A servo tank gauge (STG) is a highly precise instrument used for liquid level measurement in industrial tanks. It is commonly applied in oil, chemical, and LNG storage facilities where high accuracy, reliability, and compliance with international standards are required.

1. How a Servo Tank Gauge Works

A servo motor controls a displacer (sensor weight) that is suspended in the liquid. The gauge continuously adjusts the position of the displacer to maintain equilibrium, measuring the liquid level, interface, and density with high precision.

2. Key Features of Servo Tank Gauges

✅ High Accuracy – Measures liquid levels with millimeter precision (±0.4 mm or better).
✅ Multi-Parameter Measurement – Simultaneously measures level, density, and interface between two liquids.
✅ Continuous Monitoring – Provides real-time data for inventory management and process control.
✅ Automatic Compensation – Adjusts for factors like temperature, density changes, and tank movement.
✅ Compliance with Industry Standards – Meets API, OIML, and ISO guidelines for custody transfer and inventory control.
✅ Integration with Tank Gauging Systems – Works with SCADA, DCS, and inventory management software for remote monitoring.

3. Applications of Servo Tank Gauges

  1. Oil & Gas Storage – Measures crude oil, refined petroleum, and LNG in bulk storage tanks.
  2. Chemical Industry – Monitors liquids with varying densities and interfaces in chemical tanks.
  3. Marine & Bunkering – Ensures precise fuel measurement in ships and offshore platforms.
  4. LNG & Cryogenic Storage – Works in low-temperature environments with high accuracy.

4. Choosing the Right Servo Tank Gauge

  • Measurement Range – Select a gauge suitable for tank size and liquid type.
  • Accuracy Requirements – Choose high-precision models for custody transfer applications.
  • Explosion-Proof & Hazardous Area Certification – Essential for use in flammable liquid storage.
  • Integration with Other Sensors – Some models include temperature probes and pressure transmitters for complete tank monitoring.
  • Communication Protocols – Look for Modbus, HART, or Foundation Fieldbus compatibility for easy integration.